1. Technical Field
The present invention relates to a connector used for a flexible print circuit or a flat cable, such as a flexible flat cable, and relates more specifically to a connector that furnishes a stable electric property by providing a secure connection for a cable.
2. Related Art
Because of their thin-plate structure, flat cables is useful for wiring in narrow spaces, further is useful for use with moving parts due to the their flexibility, for instance, wire harnesses for connection between electrical equipment mounted on the doors of vehicle and vehicle body, membrane switches for transmitting electric signals when seats are occupied, and lead lines for conveying such electric signals from the membrane switches to external receptacles.
A connector used for such a flat cable when connecting a cable of cables to electric equipment is disclosed, for example, in JP-A-62-165884, and will now be described while referring to FIGS. 7 and 8. A connector 1 comprises: a housing 5, in which multiple terminals are embedded using a molding process; a cover 7 covering a terminal joints. Terminals 3 are attached by reflow soldering to conductors (44 in FIG. 1) of a flat cable 40 which is disposed perpendicular to the axial direction of the terminals 3, and the cover 7 is fitted to the housing 5 to cover the soldered terminal joints.
In this connector 1, when the cover 7 is fitted onto the housing 5, tongue pieces 9 formed on the cover 7 are engage with protrusions 11 on the housing 5, while a flat cable 40 is bent into a U shape, following the outline of the terminals 3, to provide so-called strain relief, so that the flat cable 40 can be introduced from the rear of the connector 1. Thus, the removal of soldered joints is prevented during normal use and handling, and the safety of the terminal joint is ensured.
However, for a related connector, the aligning with connector terminals of conductors comprising a flat cable is difficult, and since arranging the flat cable relative to the connector terminals is such a complicated task, the operating efficiency is not satisfactory.
Since the cover must be securely fitted to the housing without a play between the parts, highly accurate sizing and positioning must be provided for the tongue pieces and the protrusions. That is, if the cover is loose, external tension applied to the cable will also be transferred to and adversely affect the terminal joints, so that the cable/joint connections will be unstable.
To solve this problem, it is one objective of the invention to provide a connector wherewith the conductors comprising a flat cable can be easily and accurately positioned opposite the terminals accommodated in a terminal accommodation chamber, and wherewith connection stability between the cable and the terminals can be continuously maintained, even when there is a slight play between the components.
To achieve the above objective, according to the invention, a connector comprises:
a connector housing;
a terminal accommodation chamber provided in the connector housing;
a terminal including an elastic conductor joint accommodated in the terminal accommodation chamber in a terminal insertion direction;
a pair of slits, which are adapted to be passed a flat cable therethrough, respectively formed in an opposite outer walls of the terminal accommodation chamber, wherein the flat cable is inserted in the pair of slits in a direction perpendicular to the terminal insertion direction; and
a rear holder inserted into the connector housing being shiftable between and engageable at a temporary engagement position in which the flat cable is permitted to be inserted through the pair slits and a plenary engagement position wherein the rear holder and the an elastic conductor joint hold the flat cable.
When the flat cable has been passed through the pair of slits in the connector housing, and when the rear holder is shifted from the temporary engagement position to the plenary engagement position, the conductor joints is driven by the rear holder and the flat cable and are elastically bent. Then, since the recovery force produced by the bending of the conductor joint forces the joints against the flat cable, a good electrical connection can be established between the conductor joints and the flat cable.
According to the invention, in the connector of the first aspect, the base of the terminal is curved and U-shaped as the conductor joint, and when the curved faces are forcibly driven inward, the conductor joints are elastically bent.
When the base of the terminal is curved and U-shaped as the conductor joint, the curved faces, when contacted by the rear holder, are driven inward so that the conductor joints are is elastically bent. Further, the displacement value of the conductor joints can absorb the effect produces by size discrepancies between the terminals and the rear holder, so that stable contact between the terminals and the flat cable can be obtained.
According to the invention, in the connector of the first aspect, the width of the slits may be substantially equal to the width of the flat cable.
Since the widths of the slits substantially match the width of the flat cable, when the flat cable is passed through the slits, it is inscribed to the opening edges of the slits and its widthwise displacement is restricted. Thus, the flat cable can be positioned at a predetermined location, and can be arranged so that it is positioned precisely opposite the conductor joints of terminals accommodated in the terminal accommodation chamber.